<configuration>
  <!-- Note: this is a brute-force way to do things, but using properties is probably better -->

  <!-- #ifdef development -->
  <entry foo="development_value"/>
  <!-- #endif -->

  <!-- #ifdef testing -->
  <!-- <entry foo="testing_value"/> -->
  <!-- #endif -->

  <!-- #ifdef integration -->
  <!-- <entry foo="integration_value"/> -->
  <!-- #endif -->

  <!-- #ifdef production -->
  <!-- <entry foo="production_value"/> -->
  <!-- #endif -->

</configuration>